Ammunition



, sizePshot by dropshot methods;

Patented Aug. 21, 1945 toRemingtonArmSIGompanmJna, Bridgeport,

001 1., a-corporation of Delaware Application Januaryfifl, 19143; SeriahNm 474,209

1 1 Claim; (01:83-91) 'I his inventiom relates inzgeneral; to: ammunition; and; in: particular; to an improved. method and means for the productiomofidropped shot..

An object. of; the r invention is:to producerlarge A. further: object thelaperturesinrthe. form of attenuated teats.

Inzuse, molten metal is poured. into thepan to form: a substantiallythree or four inch pool of le'a'dwhicli trickles down through. the filterwand isi toz-providean-improved. dross pouring; pan for forming :largessize shot uniformly andiconsistent- The" invention. likewise includes other improvements imthe? production of shot' as fw illfherei inafterappear.

Inzgeneral, shot are: produced by=two methods;

namely, either by casting: or' by forminga'drops i of the molten metal: and-1 enabling; the drops to a fall from r a. given. height. into ax liquid baths.

. The casting; technique .iSlllSBd for the. produc .forms' large. drops onxthe bottom of. the pan at the aperturesor. atxthe: ends of? the teats When thesedrops have assumed a substantially sphericalv shape, they detach themselves. from the apertures or teatsandzfall down into. thewell. Inasmuch as the apertures differ substantiall in: size from the. attenuated teats and inasmuchas the teats themselvesvary widely in size and shape the sizes: of. the lead. shot. formed by a single dross pan of: this type have beennumerous and nontion of-relatively 'largeshot.which, inaccordance 1:.

with accepted. nomenclature;.are: termed buck shot and decrease size from:.No7.- 000 buck; shot,

uniform;

Although this typeof' dross pan has been used commercially for the production of dropped shot which is-approximately:0;36rinch:imdiameter, to i No. 4; which: is substantiallytzeninchtin diam eter; Moreover allzshot ranging: from:0.23-:'inch 1:00.21 inoh ini diameten andidentifiedas FF, F and T1: shothave: heretofore been cast;

All 1 shotsmaller than? No. is produced by either of: two. somewhat similar drop: forming methodsddentified int-heart as thel shower pa-n and dress pan techniques;

Theshower- -panisused: for? the; productionof the smallest sizes of: dropped: shot: which range from No: 12; which isapproximatelmfldinch:in

up toandiincluding 'No. Tshot, all efiorts to producedroppedshot larger than No; T, andiidentifiEdTELSaNCS. TT,.F and FF'which range from 0.21

. inch to 0.23 inch in diameter have heretofore diametento No. 4; whichissubstantially 0:130

inch in diameter: "I'heshower on frying pan from which this process takes: its? name. consists simply of a pan havingra: thimbottom' provided .Withar large number. of drilled holes? The pan is supported in-thetop of a shot tower and=when molten lead ispoured thereinr the lead passes-out throughlthe holes forming substantially spherical drops-on the bottom of the pan which detach themselves from theapertures-and? shower down into a. liquid. in the well: at. the bottomef? the tower. r In general,.audross pan is used forthe. production of shot w hich are. larger: than No; 4 dropped-r shot. but smaller. than No. Till. This range. includes dropped shot: which? increase; in size. from No. 3iwhich is substantially Odell-inch in. diameter through Nost 2, 1, B,.BB,,BBB;\ AR and T. The latter size of shotaresubstantially 0.20 inch in diameter and are-thelargestzsize' that itthas heretofore been practicable. to produce". b prior art dropped shot methods. A

Heretoforathe: drosspanhas: comprised a" relatively large receptacle: having a. comparatively thin bottom provided? with a pluralityof holes,

each .hole being substantially- 30%1arger than. the

. spread over the bottom of the pan filling the holes andquiterfrequently -exuding down through 3 been1 impracticable.

Theprimary. cause. of: this lack of success has I beensthe inability to maintainaproper dross1-bottom on the pan; Due to thermal stresses and erosion; cracks and splits: tend to form in the filter, and}. as soon. as this occurs, the molten lead poursdown: through several of the relatively large apertures in r the pan. bottom. in a' substan'- tially solid stream which causes great potential damage; to; the tower well and conveying chains andv interrupts production until. the dross bottom of: the pan: can: be repaired which; in? most instances; requires;aprohibitive length of time. Moreover, although dross pans for No. T'I shot have; been operated for short: intervals without mishap, the size of the shot produced' has been primarily No: T. shot plus a. wide variety of smaller shot. In" fact, there have been known instancesiwherrnthere wereas many astwenty or moredifierent sizes of shot fallin into the well. a. consequence, the production of shot of the required size-was practically nil. There hasbeen, therefore, notpracticable'way heretofore ofpro. ducing large quantities of .the larger sizes of shot; except by; casting; and: this method is: expensiyezarrd unsatisfactory.

The" presentuinvention provides an improved dross= pan. which" is? capable of. producing. large 'sizesrofr droppeds hot' consistent-1y, of substantial ly. uniform size; and. in: large quantity lots without: the: numerous disadvantages inherent in the equipment? and methods: heretofore used;

'Inuthedrawing: l l

Fig. 1: shows. diagrammatically 3A fragmentary elevation'partly inrsection :of adrossapan mounted at the top of a drop tower.

Fig.1 2 shows? a=:-.plan:view: of: therdross pan of this invention; l a

Fig; 3. shows. a sectional elevation of. the dross parrzofiEiglfii. l

exemplary embodiment of apparatus used in the production of dropped shot either by the shower pan or dross pan method, the panyindicated, generally at I I], is supported in a suitable housing- II which is mounted over an aperture l2 in the topmost floor 13 of the shot tower and directly above the upper end of the shot tower tube 14.

The housing H may include heating means such as the gas burners I5 for maintaining a molten lead bath in the pan. As is well understood, spherical drops of molten lead form at the apertures on the bottom of the pan. When these drops have partially congealed, they detach themselves from the bottom of the pan and fall down the tube l4 into a well of water in the base thereof from which they are collected and subsequently delivered into suitable storage bins.

Referring to Fig. 3, which shows an elevation in section of the dross pan of this invention, the pan comprises a disk-shaped bottom It of a suitable metal, such as machine steel, which, for the purposes of this specification, is substantially twenty-six inches in diameter and one-half inch thick. The disk is provided with a, central aperture H for accommodating the lower end of a cylindrical steel sleeve l8 which is welded or otherwise secured therein. The wall IQ of the pan com-prises a relatively thin sheet of steel welded at its lower edge around the periphery of the bottom It and provided with a substantially horizontally disposed rim 2!] at its upper edge. In the present embodiment, the walls of the pan converge downwardly towards the bottom of the pan. Suitable braces or reinforcing members 2!,

three being shown in the present embodiment,

are secured at their lowerends to the rim 2t and at their upper ends to the upper end of the sleeve [8.

The bottom it of the pan is provided with a plurality of holes, indicated generally at 22, see Fig. 4, and in the present embodiment number approximately 764 within the limits of the drilled area.

Each hole 22 comprises an aperture 23 drilled in the lower surface of the bottom 16, the aperture being substantially /64 of an inch deep and of an. inch in diameter. These dimensions govern the size of the shot which will be produced by this particular dross pan, and, for most satisfactory results, the diameter of each aperture is made substantially 30% greater than the actual size of the shot which forms at the aperture. I

The specific dimensions given herein are for a dross pan having apertures adapted to form No. T'I shot, but, it will be understood that the pan may comprise other equivalent materials and have other shapes and dimensions depending upon the size of shot to be formed. Each aperture 23 is provided with a concentric counterbore 24, the diameter which is substantially of an inch and which extends down from the upper surface of the bottom l6 and constitutes, in effeet, a pocket or cell above its respective aperture These counterbores or cells are to be filled with a plug of a suitable filter material 25 such as lead oxide dross. This filter material is compacted and kneaded into the individual cells in substantially the same manner used heretofore in forming a single layer of dross on the bottom of the pan. In general, the dross plugs are formed by placing the required number of lead oxide pigs in the bottom of the pouring pan and then immersing the panin a bath of molten lead. The dross pigs soon soften and the softened material may then be kneaded into the individual cells or counterbores while slowly, withdrawing the pouring pan from the lead bath. Thus, each aperture 23 of the pouring pan will, when ready for the production of lead shot, be filled by a lead plug 25 of dross or similar filter material. Moreover, due to the converging walls of each counterbore 24, the dross material tends to bridge across the upper end of'its aperture 23 thus preventing the dross fromexuding from the bottom of the aperture in the form of an attenuated teat.

In operation, when molten lead is poured into the pan, the lead will seep downslowly through the dross plugs andform substantially spherical drops of lead at the lower ends of the apertures 23. These globules of lead will subsequently detach themselves and fall in a substantially frozen condition down into the well of the tower where they will be collected and removed in the well known manner. l Since all the globules are formed at the lower ends of "the apertures 23 and not at the ends of dross teats projecting from the apertures as heretofore practiced, the drops are all of a substantially uniform size.

It will be evident that the counterbores 24 constitute means for segregating the dross into a plurality of isolated filters 25, each located over an aperture 23 so that the formation of large areas of dross susceptible to cracks and splits is obviated. Thus, even though an individual filter plug fails, the result will be simply the escape of a thin stream of lead which atomizes into a shower of fine shot directed straight down the tower and is neither hazardous nor does it interfere with the continuous production of shot. v

Although the pan shown and described is particularly suited to form size TT shot, it will be understood that similar pans having proportional dimensions may be used effectively for the production of size F and FF dropped shot.

7 A modification of the proposed dross pan is shown in Fig. 5. In this embodiment, the pan comprises the usual type of dross pan having a relatively thin bottom l6 provided with drilled apertures 23. Placed on top of this apertured bottom is a suitable'metal plate 2! substantially equal in thickness to the bottom It minus the thickness of the bottom It. The plate 21 is drilled with apertures 24 Both the apertures 24' and I6 are substantially equal in diameter to the corresponding holes 23'and 24 of the bottom shown in Fig. 4 and are adapted to be filled with filter plugs 25. This modified pan is thus substantially equivalent to the dross pan discussed above but affords a somewhat simpler and more 'GEORGE E. HYDE, JR. 

